Litsea cubeba essential oil is a natural flavoring agent renowned for its distinctive aroma and versatile properties. However, studies investigating the impact of processing methods on its flavor profile remain limited. This study utilized an electronic nose (E-nose), an electronic tongue (E-tongue), and gas chromatography-ion mobility spectrometry (GC-IMS) combined with multivariate statistical analysis to explore the impact of cold pressing, microwave-assisted cold pressing, roasting-assisted cold pressing, and steam distillation on the volatile organic compounds (VOCs) and flavor characteristics of Litsea cubeba essential oil. The results indicated that the different processing methods impacted the flavor compound composition and sensory attributes of the oil. A total of 82 VOCs were identified, with 31 being key differential compounds. Relative odor activity value (ROAV) analysis identified four key aroma-active compounds and three modifying aroma compounds. This study offers a valuable reference for process optimization and the development of flavor-directed Litsea cubeba essential oil products.
Dangui (Camellia sinensis) is an elite cultivar suitable for processing oolong tea, while the dynamic variation of its volatile organic compounds (VOCs) during processing remains unclear. Here, HS-SPME-GC–MS was performed to explore the dynamic changes in VOCs of Dangui during processing. Results showed that esters transiently accumulated during withering and then declined gradually, while terpenoids generally rose and peaked at rolling with a subsequent slight decrease. Multivariate analysis screened 17 signature VOCs, and 13 of them could form stable complexes with human olfactory receptors. Aroma wheel analysis revealed that dynamic changes in key compounds during tea processing caused continuous increases in the intensities of floral, green, minty and nutty odors. Withering and fermentation primarily regulated nutty, pungent, and woody odors, while rolling and drying dominated the expression of floral, minty, green, and fruity odors. This study clarifies Dangui's unique aroma composition and provides a theoretical foundation for post-processing aroma modulation.
